1. Field of the Invention
The present invention relates to storing and accessing information about tape cartridges.
2. Background Art
Tape is a practical and economic means for long term data storage. Typically, tape is constructed with a flexible web onto which is placed one or more coatings susceptible to changes in magnetic fields, light, and the like. This tape is stored in a cartridge having one or two reels about which the tape is wound. The cartridge is inserted into a tape drive for writing to or reading from the data tape. Typically, the cartridge has an access door which is opened when the cartridge is inserted into the tape drive. For single hub cartridges, the tape is withdrawn from the cartridge and pulled along a tape path which includes at least one tape access head. When access is completed, the tape is rewound into the cartridge. If the cartridge includes two hubs, the tape is wound between these hubs within the cartridge. The tape may be pulled from the cartridge through the access door or a tape head may be inserted into the cartridge through the access door. A cartridge containing two hubs is sometimes referred to as a cassette.
It is often important to record information about each tape cartridge. One type of information concerns the data stored on the tape held within the cartridge. This information can include, for example, a list of files stored on the tape, the time and date at which data was stored, one or more expiration dates, file ownership information, and the like. Another type of information describes the cartridge itself. For example, the cartridge may have a serial number or other identifier. This type of information can also include a descriptor of the type of cartridge, type of tape, cartridge manufacturer information, and the like. Yet another type of information is related to how the cartridge has been used. This information can include, for example, the number of times the cartridge has been loaded into a tape deck, the number of cartridge read and/or write operations, the age of the cartridge, access error data, and the like.
One technique for holding cartridge information is to include a radio frequency tag or transponder on the cartridge. This transponder includes memory holding the data of interest. This data can be accessed by a radio frequency reader when the tag is placed in proximity to the reader. Examples of radio frequency tags and radio frequency readers for use in tape cartridges are provided in U.S. Pat. Nos. 5,971,281; 6,081,857; 6,226,688; and 6,466,990; each of which is herein incorporated by reference.
One disadvantage of previous systems is that radio frequency tags and radio frequency readers are permanently affixed to cartridges and tape decks, respectively. Thus, as technology improves or customer requirements are changed, there is no ability to easily upgrade cartridges and tape drives.